Structure and activity of human TMPRSS2 protease implicated in SARS-CoV-2 activation.

Transmembrane protease, serine 2 (TMPRSS2) has been identified as key host cell factor for viral entry and pathogenesis of SARS-CoV-2. Specifically, TMPRSS2 proteolytically processes the SARS-CoV-2 Spike (S) protein, enabling virus-host membrane fusion and infection of the airways. We present here a recombinant production strategy for enzymatically active TMPRSS2 and characterization of its matured proteolytic activity, as well as its 1.95 Å X-ray cocrystal structure with the synthetic protease inhibitor nafamostat. Our study provides a structural basis for the potent but nonspecific inhibition by nafamostat and identifies distinguishing features of the TMPRSS2 substrate binding pocket that explain specificity. TMPRSS2 cleaved SARS-CoV-2 S protein at multiple sites, including the canonical S1/S2 cleavage site. We ranked the potency of clinical protease inhibitors with half-maximal inhibitory concentrations ranging from 1.4 nM to 120 µM and determined inhibitor mechanisms of action, providing the groundwork for drug development efforts to selectively inhibit TMPRSS2.

Shared decision-making needs, barriers, and facilitators of patients with newly diagnosed advanced cancer in the hospital: a multi-level, mixed-methods study.

PURPOSE: Little is known about the shared decision-making (SDM) needs, barriers, and facilitators of patients with newly diagnosed advanced cancer in the hospital. Understanding this may improve SDM and cancer care quality in this vulnerable population. METHODS: A single-site, mixed-methods study of hospitalized patients with newly diagnosed advanced cancer, caregivers, and oncologists was conducted. After discharge, patient ± caregiver semi-structured interviews exploring SDM needs, barriers, and facilitators regarding their most important upcoming cancer-related decision were conducted. Oncologists were surveyed about patient knowledge and SDM needs using closed- and open-ended questions, respectively. Thematic analysis was performed for qualitative data with a focus on themes unique to or amplified by hospitalization. Descriptive statistics and the Chi-squared test were performed for quantitative data. RESULTS: Patients and caregivers reported high SDM needs surrounding treatment and prognostic information, leading to decisional conflict. Eight themes emerged: anticipated cancer treatment decisions, variable control preferences in decision-making, high cancer-related information needs and uncertainty, barriers and facilitators to information gathering during and post hospitalization, and decision-making facilitators. Among 32 oncologists, most (56%) reported patients were poorly informed about treatment and prognosis. Oncologists reported variable expectations about patient knowledge after hospitalization, facilitators to patient decision-making, and patient uncertainty while awaiting an outpatient oncologist appointment. CONCLUSION: Patients newly diagnosed with advanced cancer in the hospital have high SDM needs and experience decisional conflict. This may be due to barriers unique to or exacerbated by hospitalization. Further research is needed to develop strategies to address these barriers and enhance the facilitators identified in this study.

Outcomes After Implant-Based Breast Reconstruction Following the National Institution of a Ban on Bacitracin Irrigation.

BACKGROUND: The use of irrigation with bacitracin-containing solution is common among surgeons, as it was widely thought to have antibacterial properties and prevent postoperative infection. Current literature, however, suggests that antibiotic-containing irrigation confers little added benefit. On January 31, 2020, the Food and Drug Administration instituted a ban on bacitracin-containing irrigation for operative use. This study aimed to determine whether bacitracin has a beneficial effect on postoperative infection rates by analyzing infection rates before and after the Food and Drug Administration ban on bacitracin irrigation. METHODS: A single-institution retrospective chart review was conducted. Eligible patients underwent implant-based breast reconstruction after mastectomy from October 1, 2016, to July 31, 2022. Procedure date, reconstruction type, patient comorbidities, use of bacitracin irrigation, postoperative infection, and secondary outcomes were collected. Univariate and multivariable logistic regression analyses were performed. RESULTS: A total of 188 female patients were included in the study. Bacitracin use did not protect against infection in univariate or multivariable analysis. Age greater than 50 years was associated with an increased risk of postoperative infection ( P = 0.0366). The presence of comorbidities, smoker status, neoadjuvant therapy treatment before surgery, implant placement, and laterality were all not significantly associated with postoperative infection development. CONCLUSIONS: The results of this study demonstrate a lack of association between bacitracin use and postoperative infection. Additional research into the optimal antibiotic for perioperative irrigation is needed, as bacitracin is not encouraged for use.

Single-dose 177Lu-PSMA-617 followed by maintenance pembrolizumab in patients with metastatic castration-resistant prostate cancer: an open-label, dose-expansion, phase 1 trial.

BACKGROUND: Checkpoint inhibitors have been shown to have limited activity in patients with metastatic castration-resistant prostate cancer. We aimed to determine whether a single dose of lutetium-177 [177Lu]-prostate-specific membrane antigen (PSMA)-617 (177Lu-PSMA-617) followed by maintenance pembrolizumab was safe and could induce durable clinical benefit. METHODS: We did an open-label, dose-expansion, phase 1 study at the University of California, San Francisco (San Fransisco, CA, USA). Eligible patients were men aged 18 years or older with progressive metastatic castration-resistant prostate cancer who had an Eastern Cooperative Oncology Group performance status of 0 or 1, had progression on one or more androgen signalling inhibitors, and at least three PSMA-avid lesions on 68Ga-PSMA-11 positron emission tomography. In part A, patients were enrolled sequentially to one of three schedules in which a single dose of 177Lu-PSMA-617 (7·4 GBq) was given intravenously 28 days before (schedule 1), concomitant with (schedule 2), or 21 days after (schedule 3) the start of maintenance intravenous pembrolizumab (200 mg every 3 weeks). In part B, 25 patients were enrolled using the recommended phase 2 schedule. The primary endpoint in part A was determination of the recommended phase 2 schedule, and in part B, the objective response rate. The analysis set included all patients who received at least one dose of pembrolizumab or 177Lu-PSMA-617. This study is registered with ClinicalTrials.gov, NCT03805594. FINDINGS: Between Aug 8, 2019 and May 7, 2022, 43 male patients were enrolled (n=18 part A [six patients per schedule]; n=25 part B), with a median follow-up of 16·5 months (IQR 12·2-21·9). Schedule 1 was selected as the recommended phase 2 schedule for part B, on the basis of safety and feasibility of administration observed in part A. In part B, 14 (56%; 95% CI 35-76) of 25 patients had a confirmed objective response. Two (5%) of 43 patients had a treatment-related adverse event of grade 3 or worse (grade 3 arthritis in schedule 2, grade 3 pneumonitis in schedule 3). One serious adverse event (one death due to aspiration pneumonia) and no treatment-related deaths were observed. INTERPRETATION: A single priming dose of 177Lu-PSMA-617 followed by pembrolizumab maintenance was safe and had encouraging preliminary activity in patients with metastatic castration-resistant prostate cancer. FUNDING: Prostate Cancer Foundation, National Cancer Institute, Novartis Pharmaceuticals, and Merck.

The effects of psychosocial determinants on post-operative complications of head and neck free flap patients.

PURPOSE: Not much is known about how pre-operative psychosocial factors affect head and neck free flap outcomes. Hence, the objective of the study is to determine if a patient's pre-operative self-perception and quality of life affect post-operative complications and hospital length of stay after free flap surgery. MATERIALS AND METHODS: This was a prospective cohort study. Patients who underwent a free flap surgery at an academic tertiary care center between January 2021 and March 2022 were asked to fill out the Rosenberg Self Esteem Scale and the Short Form 36 Health Questionnaire before surgery. A chart review of their medical records was then performed. Analysis of the data was performed using Spearman Correlation, Fisher exact test, Mann-Whitney and Multivariate Logistic Regression on STATA 15. RESULTS: Sixty-one patients (73.8 % male; mean [SD; range] age: 60.9 [14.0, 23.1-86.8]) who underwent free flap surgery agreed to participate in the study. Most of the participants were not Caucasian (59 %). The most common indication for surgery was malignancy (93 %). The post-operative complication rate was 34.4 % and included 3 hematoma (4.9 %), 3 free flap failure (4.9 %), 9 wound dehiscence (14.8 %), 10 salivary fistulas (16.4 %), and 3 aspiration pneumonia or chyle leak (4.9 %). There were no mortalities. The mean role limitations due to physical health subscore [SD; range], social functioning subscore, pain subscore, and general health subscore of the SF-36 were 61.9 [39.2, 0-100], 70.7 [27.5, 0-100], 62.1 [25.7, 0-100], and 67.8 [20.3, 20-100], respectively. On univariate analysis, decreased physical limitations, better social functioning, less pain and better general health were associated with fewer overall post-operative complications, but was not correlated with length of stay. This held true for social functioning and general health even in multivariate analysis accounting for age and smoking history. The mean Rosenberg Self Esteem Scale score was 24.3 [4.1, 13-30]. CONCLUSIONS: In this study, patients with more limited social function and worse general health had more overall post-operative complications. It is important to continue to explore how pre-operative quality of life and other psychosocial factors can affect surgical outcomes.

Jehovah's witness head and neck free flap reconstruction patient outcomes.

BACKGROUND: Jehovah's Witnesses are members of a Christian religious denomination that rejects the transfusion of whole blood and component blood products. Given new transfusion-free strategies, Jehovah's Witness patients are undergoing free flap reconstructions with increased regularity. However, outcome data remains limited. With this study, we sought to examine post-operative outcomes in Jehovah's Witness patients undergoing free flap reconstruction of the head and neck, compare their outcomes to non-Jehovah's Witness patients, and enumerate strategies to enhance the safety of transfusion-free surgery. METHODS: A retrospective chart review was carried out on 10 patients who identified as Jehovah's Witness and 63 patients who did not. Demographic information, pre-operative laboratory values, peri-operative resuscitative interventions, and peri-operative outcome measures were compiled. Descriptive data analysis, Mann-Whitney, Chi-square tests, and multivariate analysis were used. RESULTS: Jehovah's Witness patients were significantly older than non-Jehovah's Witness patients (p = 0.03) and had significantly higher ASA scores (p = 0.009). Head and neck cancer was the primary surgical indication in both groups (p = 0.71). Jehovah's witness patients have significantly less intraoperative blood loss (p = 0.011) and lower post-operative hemoglobin (p = 0.002) compared to non-Jehovah's Witness patients. While Jehovah's Witness patients had significantly higher rates of severe anemia (p = 0.014), there was no significant difference between the two groups in other post-operative complications and readmission rates even in a multivariate analysis accounting for age and ASA score. CONCLUSIONS: Free flap microvascular reconstruction can be reliably performed on Jehovah's Witness head and neck patients without an increased risk of complication. Policies such as the use of non-blood volume expanders, albumin, Epogen, perioperative iron supplementation, cell saver and acute normovolemic hemodilution are key to ensuring good outcomes.

Malignancy Rates by Bethesda Subcategory in the Pediatric Population.

INTRODUCTION: While the Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) is the most widely used method for categorizing thyroid nodules, its applicability to children is often debated. We describe our institution's experience utilizing the TBSRTC and examine the rates of malignancy in our population. METHODS: We conducted a retrospective chart review of eligible patients undergoing primary thyroidectomy at a high-volume tertiary care pediatric hospital. All patients had pre-operative fine needle aspiration. RESULTS: Of the 112 patients in our cohort, 85 (76%) were female. The median age was 15.1 years. The patients were divided into groups based on the Bethesda categorization of the fine needle aspirations of their nodules. The percentages of patients whose resection specimens showed evidence of malignancy on the surgical pathology reports were recorded as follows: category I (n = 5): 20%, category II (n = 11): 0%, category III (n = 30): 17%, category IV (n = 13): 31%, category V (n = 17): 94% and category VI (n = 36): 100%. CONCLUSION: Our findings indicate that the malignancy rates at our institution are comparable to those reported by other high-volume studies. When compared with the 2017 TBSRTC data, we found that our results were similar in many categories, with the exception of categories I and V.

Expanded use of telemedicine for thyroid and parathyroid surgery in the COVID-19 era and beyond.

BACKGROUND: The COVID-19 pandemic has greatly expanded the use of telemedicine in healthcare. Surgical thyroid and parathyroid diseases are uniquely suited for comprehensive telemedicine. The objective of this study was to compare the safety and efficacy of telemedicine with in-person preoperative visits in patients undergoing thyroid and parathyroid surgery. METHODS: Prospective cohort study of patients undergoing thyroid and parathyroid surgery at a tertiary care center in a COVID-19 hotspot from March 2020 to October 2020. Patients were divided into a telemedicine cohort, with preoperative consultation and surgical decision-making conducted via telemedicine, and a conventional in-person cohort. RESULTS: Of 94 patients, 28 were enrolled in the telemedicine cohort and 66 were enrolled in the conventional cohort. Telemedicine patients were more likely to have parathyroid disease (50% versus 24%, p = 0.02) compared with the conventional cohort, but there was no significant difference in surgery for malignancy (43% versus 56%, p = 0.27). There were no significant differences in surgical outcomes or postoperative complications between cohorts, including intraoperative blood loss (19.4 mL versus 35.5 mL, p = 0.06), postoperative length of stay (1.3 days versus 1.2 days, p = 0.93), persistent hypocalcemia (3.6% versus 0%, p = 0.30), and true vocal fold paresis (0% versus 4.5%, p = 0.55). CONCLUSIONS: With careful selection, many patients undergoing thyroid and parathyroid surgery may be safely treated using comprehensive telemedicine.

Differential treatment outcomes in BRCA1/2-, CDK12-, and ATM-mutated metastatic castration-resistant prostate cancer.

BACKGROUND: DNA damage repair mutations (DDRm) are common in patients with metastatic castration-resistant prostate cancer (mCRPC). The optimal standard therapy for this population is not well described. METHODS: A multi-institutional, retrospective study of patients with mCRPC and DDRm was conducted. Patient data, including systemic therapies and responses, were collected. The decline in prostate-specific antigen ≥ 50% from baseline (PSA50) and overall survival (OS) from the treatment start were compared by mutation and treatment type. A multivariable Cox proportional hazards model for OS was created that controlled for DDRm, first-line treatment received for mCRPC, and clinical factors. RESULTS: The most common DDRm observed among 149 men with mCRPC were BRCA1/2 (44%), CDK12 (32%), and ATM (15%). The majority received first-line abiraterone (40%) or enzalutamide (30%). The PSA50 rate with first-line abiraterone was lower for CDK12 (52%) than BRCA1/2 (89%; P = .02). After first-line abiraterone or enzalutamide, the median OS was longest with second-line carboplatin-chemotherapy (38 months) in comparison with abiraterone or enzalutamide (33 months), docetaxel (17 months), or cabazitaxel (11 months; P = .02). PSA50 responses to carboplatin-based chemotherapy were higher for BRCA1/2 (79%) than ATM (14%; P = .02) or CDK12 (38%; P = .08). In a multivariable analysis, neither the specific DDRm type nor the first-line treatment was associated with improved OS. CONCLUSIONS: Responses to standard therapies were generally superior in patients with BRCA1/2 mutations and inferior in patients with ATM or CDK12 mutations. The DDRm type did not independently predict OS. After progression on first-line abiraterone or enzalutamide, carboplatin-based chemotherapy was associated with the longest OS. These findings may inform treatment discussions and clinical trial design and require prospective validation.

High-Contrast CXCR4-Targeted 18F-PET Imaging Using a Potent and Selective Antagonist.

C-X-C chemokine receptor 4 (CXCR4) is highly expressed in cancers, contributing to proliferation, metastasis, and a poor prognosis. The noninvasive imaging of CXCR4 can enable the detection and characterization of aggressive cancers with poor outcomes. Currently, no 18F-labeled CXCR4 positron emission tomography (PET) radiotracer has demonstrated imaging contrast comparable to [68Ga]Ga-Pentixafor, a CXCR4-targeting radioligand. We, therefore, aimed to develop a high-contrast CXCR4-targeting radiotracer by incorporating a hydrophilic linker and trifluoroborate radioprosthesis to LY2510924, a known CXCR4 antagonist. A carboxy-ammoniomethyl-trifluoroborate (PepBF3) moiety was conjugated to the LY2510924-derived peptide possessing a triglutamate linker via amide bond formation to obtain BL08, whereas an alkyne ammoniomethyl-trifluoroborate (AMBF3) moiety was conjugated using the copper-catalyzed [3+2] cycloaddition click reaction to obtain BL09. BL08 and BL09 were radiolabeled with [18F]fluoride ion using 18F-19F isotope exchange. Pentixafor was radiolabeled with [68Ga]GaCl3. Side-by-side PET imaging and biodistribution studies were performed on immunocompromised mice bearing Daudi Burkitt lymphoma xenografts. The biodistribution of [18F]BL08 and [18F]BL09 showed tumor uptake at 2 h postinjection (p.i.) (5.67 ± 1.25%ID/g and 5.83 ± 0.92%ID/g, respectively), which were concordant with the results of PET imaging. [18F]BL08 had low background activity, providing tumor-to-blood, -muscle, and -liver ratios of 72 ± 20, 339 ± 81, and 14 ± 3 (2 h p.i.), respectively. [18F]BL09 behaved similarly, with ratios of 64 ± 20, 239 ± 72, and 17 ± 3 (2 h p.i.), respectively. This resulted in high-contrast visualization of tumors on PET imaging for both radiotracers. [18F]BL08 exhibited lower kidney uptake (2.2 ± 0.5%ID/g) compared to [18F]BL09 (7.6 ± 1.0%ID/g) at 2 h p.i. [18F]BL08 and [18F]BL09 demonstrated higher tumor-to-blood, -muscle, and -liver ratios compared to [68Ga]Ga-Pentixafor (18.9 ± 2.7, 95.4 ± 36.7, and 5.9 ± 0.7 at 2 h p.i., respectively). In conclusion, [18F]BL08 and [18F]BL09 enable high-contrast visualization of CXCR4 expression in Daudi xenografts. Based on high tumor-to-organ ratios, [18F]BL08 may prove a valuable new tool for CXCR4-targeted PET imaging with potential for translation. The use of a PepBF3 moiety is a new approach for the orthogonal conjugation of organotrifluoroborates for 18F-labeling of peptides.

Use of fibrin adhesive for preventing pharyngocutaneous fistula in total laryngectomy.

BACKGROUND: Minimizing pharyngocutaneous fistula after total laryngectomy is a perpetual focus for head and neck surgeons. Multiple intrinsic and extrinsic factors have been implicated in the wound healing process. Activated fibrin glue uniquely promotes healing as a tissue adhesive as well as a biochemical growth factor. METHODS: We present a pilot case series of total laryngectomy with simple pharyngeal closure with a single surgeon. Fibrin tissue adhesive was incorporated in all patients along with standardized pre-operative, operative, and post-operative care. Outcomes measured included pharyngocutaneous fistula rate, perioperative complications, and other wound complications as well as long term swallowing function and voice rehab outcomes. We also present a review of the literature for the theoretical basis of using fibrin glue as well as other similar applications. RESULTS: Fibrin tissue adhesive was successfully used in 18 consecutive patients undergoing total laryngectomy and pharyngoplasty. Despite the presence of a variety of wound healing risk factors including prior radiation and tobacco use, there were no pharyngocutaneous fistulas or other significant wound problems. No locoregional or free tissue overlay flap was done. CONCLUSION: Fibrin tissue glue is a readily available, easily applied, and cost-effective adjunct that may reduce pharyngocutaneous fistula.

Comparison of biological properties of [177 Lu]Lu-ProBOMB1 and [177 Lu]Lu-NeoBOMB1 for GRPR targeting.

The gastrin-releasing peptide receptor (GRPR) is overexpressed in prostate cancer and other solid malignancies. Following up on our work on [68 Ga]Ga-ProBOMB1 that had better imaging characteristics than [68 Ga]Ga-NeoBOMB1, we investigated the effects of substituting 68 Ga for 177 Lu to determine if the resulting radiopharmaceuticals could be used with a therapeutic aim. We radiolabeled the bombesin antagonist ProBOMB1 (DOTA-pABzA-DIG-D-Phe-Gln-Trp-Ala-Val-Gly-His-Leu-ψ-Pro-NH2 ) with lutetium-177 and compared it with [177 Lu]Lu-NeoBOMB1 (obtained in 54.2 ± 16.5% isolated radiochemical yield with >96% radiochemical purity and 440.8 ± 165.1 GBq/µmol molar activity) for GRPR targeting. Lu-NeoBOMB1 had better binding affinity for GRPR than Lu-ProBOMB1 (Ki values: 2.26 ± 0.24 and 30.2 ± 3.23nM). [177 Lu]Lu-ProBOMB1 was obtained in 53.7 ± 5.4% decay-corrected radiochemical yield with 444.2 ± 193.2 GBq/µmol molar activity and >95% radiochemical purity. In PC-3 prostate cancer xenograft mice, tumor uptake of [177 Lu]Lu-ProBOMB1 was 3.38 ± 1.00, 1.32 ± 0.24, and 0.31 ± 0.04%ID/g at 1, 4, and 24 hours pi. However, the uptake in tumor was lower than [177 Lu]Lu-NeoBOMB1 at all time points. [177 Lu]Lu-ProBOMB1 was inferior to [177 Lu]Lu-NeoBOMB1, which had better therapeutic index for the organs receiving the highest doses.

[68Ga]Ga/[177Lu]Lu-BL01, a Novel Theranostic Pair for Targeting C-X-C Chemokine Receptor 4.

C-X-C chemokine receptor type 4 (CXCR4) is overexpressed in hematological and solid malignancies. LY2510924 is a potent peptide antagonist of CXCR4. A derivative of LY2510924, BL01, was evaluated for theranostic applications targeting CXCR4. Methods: BL01 was synthesized by solid phase approach. A Lys(ivDde) residue was added at the C-terminus of LY2510924 (cyclo[Phe-Tyr-Lys(iPr)-d-Arg-2-Nal-Gly-d-Glu]-Lys(iPr)-NH2). A DOTA chelator was conjugated to the side chain of the deprotected exogenous Lys residue. The binding affinity of Ga/Lu-BL01 was determined by competitive radioligand binding assays. BL01 was radiolabeled with 68GaCl3 or 177LuCl3. Biodistribution studies were performed in mice bearing Daudi Burkitt's lymphoma tumor xenografts at selected time points. PET imaging studies were performed with [68Ga]Ga-BL01, with blocking experiments performed with preinjection of LY2510924. The stability of [68Ga]Ga/[177Lu]Lu-BL01 was assessed in mouse plasma. Results: Ga-BL01 and Lu-BL01 have nanomolar affinity for CXCR4. [68Ga]Ga-BL01 was obtained in 58 ± 5% decay-corrected radiochemical yields and >99% radiochemical purity with a molar activity of 40 ± 11 GBq/µmol, while [177Lu]Lu-BL01 was obtained in 65 ± 6% decay-corrected radiochemical yields and >99% radiochemical purity with a molar activity of 120 ± 21 GBq/µmol. [68Ga]Ga-BL01 and [177Lu]Lu-BL01 were excreted primarily through the renal pathway. Daudi xenografts were clearly delineated in PET images with good contrast. On the basis of biodistribution data, tumor uptake of [68Ga]Ga-BL01 was 10.2 ± 2.56% injected dose per gram (%ID/g) at 1 h postinjection (p.i.). Spleen (12.6 ± 2.36 %ID/g) and lungs (13.2 ± 2.98 %ID/g), organs that express CXCR4, had high uptake as well. Preinjection of LY2510924 reduced average uptake of [68Ga]Ga-BL01 in tumors by 88%, demonstrating target specificity. The uptake of [68Ga]Ga-BL01 in tumor increased to 15.3 ± 1.86 %ID/g at 2 h p.i., with improved contrast. [177Lu]Lu-BL01 has similar pharmacokinetics as [68Ga]Ga-BL01 at 1 h p.i. The highest uptake was observed in tumor (14.0 ± 1.11 %ID/g), followed by the lungs (13.0 ± 1.27 %ID/g) and spleen (11.6 ± 1.78 %ID/g). The tumor uptake increased to 16.2 ± 2.69 %ID/g at 4 h p.i., before declining slightly to 10.1 ± 1.41 %ID/g at 24 h p.i. Both compounds were stable in vivo, as no metabolites were observed at 5 min p.i. Conclusions: [68Ga]Ga-BL01 and [177Lu]Lu-BL01 are a promising theranostic pair for imaging and endoradiotherapy of CXCR4-expressing malignancies.

Accuracy of Information Provided by ChatGPT Regarding Liver Cancer Surveillance and Diagnosis.

ChatGPT did not reliably provide accurate information to 20 questions about liver cancer surveillance and diagnosis, as assessed by six physicians who actively diagnose and/or treat liver cancer. Answers deemed inaccurate commonly related to questions on specific LI-RADS categories and included contradictory or falsely reassuring, if not wrong, information.

Synthesis and evaluation of an 18 F-labeled trifluoroborate derivative of 2-nitroimidazole for imaging tumor hypoxia with positron emission tomography.

2-Nitroimidazole-based hypoxia imaging tracers such as 18 F-FMISO are normally imaged at late time points (several hours post-injection) due to their slow clearance from background tissues. Here, we investigated if a hydrophilic zwitterion-based ammoniomethyl-trifluoroborate derivative of 2-nitroimidazole, 18 F-AmBF3 -Bu-2NI, could have the potential to image tumor hypoxia at earlier time points. AmBF3 -Bu-2NI was prepared in 4 steps. 18 F labeling was conducted via 18 F-19 F isotope exchange reaction, and 18 F-AmBF3 -Bu-2NI was obtained in 14.8 ± 0.4% (n = 3) decay-corrected radiochemical yield with 24.5 ± 5.2 GBq/µmol specific activity and >99% radiochemical purity. Imaging and biodistribution studies in HT-29 tumor-bearing mice showed that 18 F-AmBF3 -Bu-2NI cleared quickly from blood and was excreted via the hepatobiliary and renal pathways. However, the tumor was not visualized in PET images until 3 hours post-injection due to low tumor uptake (0.54 ± 0.13 and 0.19 ± 0.04%ID/g at 1 and 3 hours post-injection, respectively). The low tumor uptake is likely due to the highly hydrophilic motif of ammoniomethyl-trifluoroborate that prevents free diffusion of 18 F-AmBF3 -Bu-2NI across the cell membrane. Our results suggest that highly hydrophilic 18 F-labeled ammoniomethyl-trifluoroborate derivatives might not be suitable for imaging intracellular targets including nitroreductase, a common tumor hypoxia imaging target.

Microvascular replantation of a composite facial avulsion in a 24-month-old child after dog bite.

Dog bite injuries are common sources of morbidity with an estimated incidence of 4.5 million bites per year with over 350,000 requiring treatment in the emergency room. Children under the age of 14 are most likely to be affected with a peak age of 5-9 years old. We report a case of a 24-month-old female who sustained a large composite facial avulsion injury from a pit bull dog bite. The avulsed tissue involved a substantial portion of the patient's mid-face, including the entire soft tissue of the nose, upper lip, part of the left cheek, and left oral commissure. Artery-only microvascular replantation was performed because no recipient vein could be identified from the facial defect. Medicinal leech therapy was used for eight days postoperatively to prevent venous congestion. The patient experienced significant blood loss due to leech therapy and required nearly 29 L of blood product replacement. At the last follow up of 8 months postoperatively, the patient was recovering well with significant improvement in function and cosmesis of the mid-face. This case describes a successful artery-only replantation of an avulsive bite injury to the face of a young child. Despite the technical difficulty of cases such as this one, microvascular replantation should be attempted because when successful it provides a superior cosmetic and functional result to other reconstructive techniques.

Cellular heterogeneity profiling by hyaluronan probes reveals an invasive but slow-growing breast tumor subset.

Tumor heterogeneity confounds cancer diagnosis and the outcome of therapy, necessitating analysis of tumor cell subsets within the tumor mass. Elevated expression of hyaluronan (HA) and HA receptors, receptor for HA-mediated motility (RHAMM)/HA-mediated motility receptor and cluster designation 44 (CD44), in breast tumors correlates with poor outcome. We hypothesized that a probe for detecting HA-HA receptor interactions may reveal breast cancer (BCa) cell heterogeneity relevant to tumor progression. A fluorescent HA (F-HA) probe containing a mixture of polymer sizes typical of tumor microenvironments (10-480 kDa), multiplexed profiling, and flow cytometry were used to monitor HA binding to BCa cell lines of different molecular subtypes. Formulae were developed to quantify binding heterogeneity and to measure invasion in vivo. Two subsets exhibiting differential binding (HA(-/low) vs. HA(high)) were isolated and characterized for morphology, growth, and invasion in culture and as xenografts in vivo. F-HA-binding amounts and degree of heterogeneity varied with BCa subtype, were highest in the malignant basal-like cell lines, and decreased upon reversion to a nonmalignant phenotype. Binding amounts correlated with CD44 and RHAMM displayed but binding heterogeneity appeared to arise from a differential ability of HA receptor-positive subpopulations to interact with F-HA. HA(high) subpopulations exhibited significantly higher local invasion and lung micrometastases but, unexpectedly, lower proliferation than either unsorted parental cells or the HA(-/low) subpopulation. Querying F-HA binding to aggressive tumor cells reveals a previously undetected form of heterogeneity that predicts invasive/metastatic behavior and that may aid both early identification of cancer patients susceptible to metastasis, and detection/therapy of invasive BCa subpopulations.